Cardiac rhythm management devices are implantable devices that provide electrical stimulation to selected chambers of the heart in order to treat disorders of cardiac rhythm and include pacemakers and implantable cardioverter/defibrillators. A pacemaker is a cardiac rhythm management device that paces the heart with timed pacing pulses. The term “pacemaker” as used herein, however, should be taken to mean both pacemakers and any device with a pacing functionality, such as an implantable cardioverter/defibrillator with a pacemaker incorporated therein.
Implantable medical devices are typically configured to record physiological data from sensing channels such as cardiac electrograms. The data is stored in memory so that it can be later downloaded via a telemetry link and used for patient and/or device evaluation. Because an implantable device has a very limited data storage capacity, it is conventional for such devices to the record physiological data in a rolling fashion where older data is continuously overwritten by newer data. Upon the death of the patient in whom such a device is implanted, the device will continue to record blank data which overwrites the data collected shortly before the actual death event. Such data would be useful, however, to clinicians and forensic investigators in determining the cause of death.